^ I'd say it was the hard work and physical activity, but also the quality of the food available that kept people in the 1920's lean as I'd naively guess that back then, foods were a lot less processed and people relied on local sourcing, if not direct production a lot more so with less odds (and engineering) for artificial chemical alterations. Also I think all the constant advertising in modern media subconsciously influences people to keep eating more and more bullshit, it's just crazy how every new thing keeps marketing itself as topping the former so as a consumer you're in the way of the competition between different corporations fighting over your money and all you get back is poorer and poorer product passed off as the latest derivative. Fast food is everywhere including on the Internet, the whole industry to me seems to be in the process of turning into something else that may or may not be leading to the masses essentially forgetting how to cook or even think cooking, ingredients, nutrients as dependency to specific items and brands (including convenient delivery services). But each step your food has to go through depletes its quality and in the end I think a lot of obesity directly has to do with that cognitive dissonance where instead of looking at food naturally as in for what its intake represents for their body, they just consume whatever they see thrown their way and in a way they lose touch with what their body really needs and is actually trying to tell them through their bad habits.
Smoking does the same to me, working as an appetite suppressant which seems to trip my friends out when I tell them, but it's true that the time period where I started losing weight/getting into that 'diet' as opposed to the classic 3-meal-a-day and the one I started smoking daily coincide, in general I think smoking has only ever been making me more in touch with my real needs though and I guess now I'm just not eating many times that I otherwise would have but unnecessarily.
Gotcha on working from home being tough, yeah it's easy to get your eating and sleeping patterns all fucked up, having a separate studio for work would probably help separate both worlds a lot otherwise if you lack structure (which I think is key here) it's easy to just work all the time, into the night/earling morning and forget to eat when you're overwhelmed. I think it's about finding the patterns that work best for you and then turning that into a work ethic. I don't have kids though and get to smoke and skate whenever current work and weather allow, actually really thankful for that freedom right now, I guess it's one of the few perks of 2020 being plain shit.